@import "juzhong";
*{
  margin: 0;
  padding: 0;
}
#out{
  position: relative;
  width: 300px;
  height: 300px;
  border: 1px solid;
  margin: 0 auto;
  .in{
  //.in:extend(.juzhong){
    &:extend(.juzhong all);
    &:nth-child(1){
      width: 100px;
      height: 100px;
      background-color: pink;
    }
    &:nth-child(2){
      width: 50px;
      height: 50px;
      background-color: yellow;
    }
  }
}

